Which feature is common between both the DIVIDED HIGHWAY and HILL signs?

The correct answer is that both the DIVIDED HIGHWAY and HILL signs have a yellow background. In traffic sign design, a yellow background is used to indicate caution and warning. This color is universally recognized as a signal for drivers to be attentive and prepared for potential hazards on the road.

Having a yellow background ensures that these signs stand out against various environments, providing clear visibility to drivers which is crucial for safety. The DIVIDED HIGHWAY sign warns drivers that the road ahead is divided, while the HILL sign warns of an upcoming hill or incline, both of which are important for drivers to recognize in order to navigate safely.

In contrast, while the other options may apply to some traffic signs, they do not specifically relate to both signs in question. The presence of vehicles is common in some signs but not in these particular warning signs. Similarly, while both signs can be seen as warning drivers of different conditions on the road, not all warning signs depict obstacles. The aspect of guiding traffic direction does not apply to either sign as they are primarily cautionary indicators.